Schools of Dentistry, Griffith University, Queensland, Australia.
Pathology. 2012 Apr;44(3):221-7. doi: 10.1097/PAT.0b013e3283513f3b.
This study investigates whether matrix metalloproteinases (MMPs), specifically MMP-2 and MMP-9, interacting with other molecules important in osteoblast differentiation and osteoclastogenesis, could play important roles in the invasion of bone by oral squamous cell carcinoma (OSCC).
Supernatant (conditioned medium, CM) was collected from OSCC cell lines (SCC15 and SCC25), and from cultured osteoblasts (hFOB cell line and a primary culture, OB), and used for indirect co-culture: OSCC cells were treated with CM from osteoblasts and vice versa. Zymogenic activities of MMP-2 and -9, and protein quantities of all molecules studied, were detected by gelatine zymography and Western blotting, respectively. Real-time polymerase chain reaction (PCR) analysed mRNA of these molecules. Targeted molecules were examined by immunohistochemistry in tissue sections of bone-invasive OSCCs.
Zymogenic activities of both MMPs were increased in OSCC cells following culture with CM from hFOB: Twist1 protein expression was increased while Runx2 did not alter. The RANKL/OPG ratio, zymogen and protein expression of MMP-9 were increased in hFOB cells cultured with CM from OSCC lines, while zymogen expression of MMP-2 was decreased. Real-time PCR showed generally similar changes in expression of these molecules. All targeted molecules were expressed in invading malignant keratinocytes, and all but OPG were expressed in osteoclasts of clinical samples.
Crosstalk between different cell types appears to exist in the invasion of bone by OSCC. Understanding and ultimately interfering with the molecules involved may provide therapeutic approaches to inhibit such bone invasion.
本研究旨在探讨基质金属蛋白酶（MMPs），特别是 MMP-2 和 MMP-9，与其他在成骨细胞分化和破骨细胞生成中起重要作用的分子相互作用，是否在口腔鳞状细胞癌（OSCC）侵犯骨骼中发挥重要作用。
收集 OSCC 细胞系（SCC15 和 SCC25）和培养的成骨细胞（hFOB 细胞系和原代培养 OB）的上清液（条件培养基，CM），并用于间接共培养：用成骨细胞 CM 处理 OSCC 细胞，反之亦然。通过明胶酶谱法和 Western blot 分别检测 MMP-2 和 MMP-9 的酶原活性和所有研究分子的蛋白量。实时聚合酶链反应（PCR）分析这些分子的 mRNA。通过免疫组织化学检查骨侵袭性 OSCC 组织切片中这些分子的表达。
用 hFOB 的 CM 培养后，OSCC 细胞中两种 MMP 的酶原活性均增加：Twist1 蛋白表达增加，而 Runx2 不变。在 hFOB 细胞中，用 OSCC 细胞系的 CM 培养后，RANKL/OPG 比值、MMP-9 的酶原和蛋白表达增加，而 MMP-2 的酶原表达减少。实时 PCR 显示这些分子的表达也有类似的变化。所有靶分子在侵袭性恶性角质形成细胞中表达，除 OPG 外，所有靶分子在临床样本中的破骨细胞中表达。
不同细胞类型之间的串扰似乎存在于 OSCC 侵犯骨骼的过程中。了解并最终干预所涉及的分子可能为抑制这种骨侵犯提供治疗方法。
